1. Field of the Invention
The present invention relates generally to the field of storm doors and panels for protectively covering building openings. More specifically, the present invention relates to a composite panel apparatus which includes a series of curved elongate plates hingedly interlocked along their longitudinal edges. This composite panel is deployed along lateral guide members over a building opening, such as a door or a window, by partially unfolding the plates vertically in accordion fashion. Each plate remains angled with respect to the next plate to produce a series of peaks and valleys resulting in an inventively corrugated composite panel. The corrugations substantially enhance the panel strength against the impact of airborne objects in storm winds. The panel is further strengthened by the cross-sectional curvature of the plates and by the inventive double stop hinge structures formed at the longitudinal plate edges. This specially configured, curved and preferably uninterrupted plate cross-section permits the plates to collapse substantially face to face when the panel is folded for storage, the closeness and compactness of the plates being limited only by contact between adjacent plate hinge structures.
2. Description of the Prior Art
There have long been shutters and panels for covering openings in buildings and vehicles. Some of these structures have been intended for protection against storm winds and flying debris, and yet lack sufficient strength to do the job reliably. In addition, they are either impractical or unappealing because they are bulky, obstructive and conspicuous, or have too many separate parts to be economical to manufacture.
Duda, U.S. Pat. No. 4,634,172, issued on Jan. 6, 1987, discloses a rain sealing mechanism for securing a panel to a recreational vehicle. The panel shown in the Duda patent is intended to be merely incidental to a flexible connector which secures the panel. Yet for purposes of the present application, the Duda panel is of greater interest. Duda illustrates a deployable panel formed of a series of elongate plates having pivotally interlocking opposing edges including a C-shaped rail along one edge and a bead along the opposing edge. The rail and bead are sized so that the bead of one plate is retained within the rail of an adjacent plate. The composite panel is stored by gathering the interlocking plates into a roll on a spool. The width of the opening in the C-shaped rail is such that the adjacent panel abuts one edge of the opening when the panel is fully opened and abuts the other opening edge when the panel is fully closed. A problem with Duda if used for storm protection is that the deployed panel presents a substantially planar composite sheet, which is relatively susceptible to bending and crushing failure from object impact. Another problem is that the locking strength of the plate edge structure is limited to the abutment of a plate face against a single opening edge in an adjacent plate. Still another problem is that the plates forming the panels cannot be collapsed face-to-face for compact storage.
Frey, U.S. Pat. No. 4,128,120, issued on Dec. 5, 1978, and Schijf, U.S. Pat. No. 4,644,724, issued on Feb. 24, 1987, both reveal panels made up of plates very similar to those of Duda. Frey and Schijf once again have a C-shaped channel along one plate edge interlocking with a bead along an adjacent plate edge, and open into a substantially planar configuration. As a result, Frey and Schijf present the problems of Duda.
Barber, U.S. Pat. No. 4,433,714, issued on Feb. 28, 1984, teaches a roller shutter door formed of a series of horizontal plates with pivotably inter-engaged edges. One edge is curved back over the plate to form a C-shaped cross-section, and the opposite edge is curved back over the opposite side of the plate in a slightly smaller C-shaped cross-section. The smaller C-shaped edge of one plate fits into the larger C-shaped edge of an adjacent plate. To reduce slackness between the interlocking plate edges, a strip of resilient material is placed inside the smaller C-shaped edge. The plates are bowed to provide a certain degree of corrugation in the deployed panel, but there is a lack of strength at the edge joints which is similar to that described above for Duda. Another problem is that the plates are all convex in the same direction, and thus cannot be collapsed face-to-face into a compact stack.
Kurz, U.S. Pat. No. 3,516,470, issued on Jun. 23, 1970, illustrates a removable storm shutter including a series of hingedly interlocking plates. These plates ride in side channels to collapse substantially in a stack and to deploy into a substantially planar storm panel. Kurz presents the problems identified for Duda. The cross-sectional shape of the plates prevents them from collapsing to an extent that hinges abut. See FIG. 3.
Ruppel, U.S. Pat. No. 4,723,588, issued on Feb. 9, 1988, and Machill, U.S. Pat. No. 4,972,894, issued on Nov. 27, 1990, disclose similar versions of a roller shutter or curtain. The shutters are formed of a series of elongate plates, each having two spaced apart sheet metal face portions closed at their mutual edges. The plates are either left hollow, or are filled with an insulating material. A C-shaped channel is formed at one longitudinal edge, having a flange engagement portion extending part way across its open end. The other longitudinal edge is bent back into a hook-shaped curve to fit into the channel of an adjacent plate and to hingedly interlock with the flange engagement portion along the channel. The problems of Ruppel and Machill are similar to those of Kurz and Duda. Also, as in Barber, the plates are all convex in the same direction, preventing compact face-to-face collapse.
Susnar, U.S. Pat. No. 5,099,904, issued on Mar. 31, 1992, reveals a folding security shutter. The Susnar shutter is formed of an interlocking series of vertical plates riding in top and bottom tracks. During assembly, a bead on each plate longitudinal edge slides into one of two channels in a separate hinge strip. One hinge strip is needed to connect each adjacent pair of plates edges. A problem with Susnar is that the plates and hinge strips are separate pieces, requiring the cost of two extrusions rather than one, and the further cost of assembling the hinge strips and plates.
Panels formed of plates which do not collapse face-to-face include those disclosed in Machill, U.S. Pat. No. 4,972,894, issued on Nov. 27, 1990; Frey, U.S. Pat. No. 4,128,120, issued on Dec. 5, 1978, and Jones, U.S. Pat. No. 4,037,639, issued on Jul. 26, 1977. The plates of Gates, U.S. Pat. No. 3,924,671, issued on Dec. 9, 1975, fold convex face to convex face and thus do not become fully compact. Still other patents covering loosely related subject matter include Auten, U.S. Pat. No. 2,351,656, issued on Jun. 20, 1944; McCabe, U.S. Pat. No. 3,401,734, issued on Sep. 17, 1968; and Snyder, U.S. Pat. No. 2,641,018, issued on Jun. 9, 1953.
It is thus an object of the present invention to provide a folding storm panel apparatus which forms a composite panel with pronounced corrugations when deployed, for reliable strength against wind-driven projectiles.
It is another object of the present invention to provide such a panel apparatus which has double-locking characteristics for stronger joints between deployed plates, again to withstand projectile impact.
It is another object of the present invention to provide such a panel apparatus formed of plates which are cross-sectionally bowed for strength across a wide span and yet are configured cross-sectionally to be capable of collapsing face-to-face and thus occupy minimal space.
It is still another object of the present invention to provide such a panel apparatus in which each plate and its plate hinge structures may be extruded together as one piece for simplicity and minimized cost.
It is finally an object of the present invention to provide such a panel apparatus which is relatively inexpensive to manufacture, install and maintain.